Flavoring and fragrance compositions and processes

ABSTRACT

Processes for altering the flavors and aromas of consumable products, including foodstuffs and tobaccos, which comprise adding thereto a small but effective amount of at least one tricyclic pyrazine having the formula   WHEREIN M AND N ARE EACH AN INTEGER FROM ONE TO SIX, AND R1, R2, R3, R4, R5, R6, R7, and R8, are the same or different and represent hydrogen or alkyl; the products so produced; flavoring and fragrance compositions containing such tricyclic pyrazines; and certain novel pyrazines and processes for their production.

United States Patent 1191 Pittet et al.

[111 3,754,934 1 Aug. 28, 1973 FLAVORING AND FRAGRANCE COMPOSITIONS ANDPROCESSES [75] Inventors: Alan 0. Pittet, Atlantic Highlands;

Ranya Muralldhara, Matawan, both of NJ.

[7 3] Assignee: International Flavors & Fragrances Inc., New York, NY.

221 Filed: Nov.2, 1971 [21] Appl.No.: 195,006

Related U.S. Application Data [62] Division of Ser. No. 75,782, Sept.25, 1970, Pat. No.

[52] U.S. CI 99/140 R, 131/17, 131/144,

[51] Int. Cl. A231 l/26, C07d 51/76 [58] Field of Search 99/140 R;131/17, 131/144; 260/250 R [56] References Cited UNITED STATES PATENTS9/1968 Roberts 99/1'40 R 3,686,177 8/1972 Pittet et a1. 99/140 R3,705,158 12/1972 Pittet et a1. 99/140 R FOREIGN PATENTS OR APPLICATIONS1,156,484 6/1969 Great Britain OTHER PUBLICATIONS Chemical Abstracts,65:2646b (1966). Sax, Dangerous Properties of Industrial Matls, ThirdEdition, Reinhold Book Comp., NY. (1969) pp. 934,

Primary Examiner-Morris O. Wolk Assistant Examiner-Sidney MarantzAttorney- Lorimer P. Brooks, Harold Haidt et a1.

[57] ABSTRACT Processes for altering the flavors and aromas ofconsumable products, including foodstuffs and tobaccos, which compriseadding thereto a small but effective amount of at least one tricyclicpyrazine having the formula wherein m and n are each an integer from oneto six, and R R R R R R R and R are the same or different and representhydrogen or alkyl; the products so produced; flavoring and fragrancecompositions containing such tricyclic pyrazines; and certain novelpyrazines and processes for their production.

7 Claims, No Drawings FLAVORING AND FRAGRANCE COMPOSITIONS AND PROCESSESThis application is a division of United States application Ser. No.75,782 filed Sept. 25, 1970, now U.S. Pat. No. 3,705,121.

BACKGROUND OF THE INVENTION The present invention relates to tricyclicpyrazines and their use in processes and compositions for altering theflavors and aromas of various materials such as tobaccos, foodstuffs,and the like, as well as certain novel pyrazines and processes forproducing them.

Because of the tremendous consumption of foods, tobaccos, and othermaterials, there has been an increasing interest in substances andmethods for imparting flavors to such consumable materials. Thisinterest has been stimulated not only because of the inadequate quantityof natural flavoring materials available, but perhaps even moreimportantly, because of the need for materials which can convey certainnuances, will be more stable than natural materials, will blend betterwith other flavors or flavoring composition components, and willgenerally provide superior products.

There have recently been suggestions that certain pyrazine derivativeshave flavors which might be useful in foods and other consumablematerials. For example, tetramethylpyrazine has been suggested for usewith vanillin in chocolate flavors, acetylpyrazine has been used intobacco and foods, and methoxypyrazine has been said to impart anut-like flavor to foods. Pyrazino[b]cyclopentanes have also beensuggested.

THE INVENTION cyclic pyrazine having the formula t a R7 /N\ R Dm 2)n REQQN wherein m and n are each an integer from 1 to 6, inclu sive; and R RR R R R R and R represent hydrogen or alkyl and are the same ordifferent. The invention also contemplates flavoring and fragrancecompositions containing such tricyclic pyrazines.

More specifically, the tricyclic pyrazines according to this inventionare pyrazines to the b" and e" sides of which are fused flvetoten-membered hydrocarbon rings. Such rings can be substituted with oneor more alkyl groups. In some instances one or the other of the ringscan be substituted with an alkadienyl group. It will be appreciated fromthe present disclosure by those skilled in the art that one or morepairs of the alkyl groups substituent on the hydrocarbon ring can begeminal, i.e, can be attached to the same ring carbon atom. It isgenerally preferred in practicing the present invention that thesubstituents be hydrogen or a lower alkyl group, particularly one havingfrom one to three carbon atoms.

A tricyclic pyrazine for use herein is l ,2,3,4,6,7,8,9-octahydrophenazine having the formula i 1 UNA/ This yellowish viscousliquid has fried corn chip odor and flavor characteristics, as furtherdescribed hereinafter.

Another tricyclic pyrazine according to this invention isl-methyl-2,3,5,6,7,8-hexahydro-1(H)-cyclopen ta-[b]quinoxaline havingthe formula This substance is a pale yellowish liquid having a nutlikearoma.

A further tricyclic pyrazine used herein is the novel materiall,2,3,4,6,7,8,9,10,11,12,13- dodecahydrocyclo-deca[blquinoxaline havingthe formula O m N This oily material has a light, sweet nut flavor andaroma character.

The following intermediates are particularly useful in the preparationof the various tricyclic pyrazines:

ta[b l-quinoxaline;

l,2,3,4,4a,6,7,8,9, l Oa-decahydrophenazine;

1,2,3,4,4a,6,7,8,9,l0,11,12,13,14atetradecahydrocyclo-deca[b]quinoxaline;and 1,2,3 ,4 4a,6,7,8,9,9a -decahydrophenazine:

R1 R1 Ra Re L z -N" R5 R2 R. R5

wherein m and n are different integers from one to six, inclusive; twoor three of the dashed lines represent non-allenic double bonds; and R.,R R R R R R and R are hydrogen or lower alkyl. When alkyl groups arepresent in these tricyclic pyrazines or tricyclic dihydropyrazines, theyare preferably lower alkyl having from one to three carbon atoms.

The tricyclic pyrazines prepared according to the present invention canbe obtained by a number of reaction routes, as by reacting a1,2-diaminocycloalkane or monoalkylor polyalkyl-substituted l ,2-diaminocycloalkane with a 1,2-cycloalkanedione or monoalkylorpolyalkyl-substituted derivatives thereof under ring-closing conditionsor by reacting such l,2 diaminocycloalkanes or derivatives with a 1,2-cycloalkane dione or monoalkylor polyalkylsubstituted derivativesthereof, followed by aromatization of the heterocyclic ring, or with a2- halocycloralkanone or monoalkylor polyalkylsubstituted derivativesthereof; or by reacting a 2- aminocycloalkanone or monoalkylorpolyalkylsubstituted derivatives thereof with a like or a differentZ-aminocycloalkanone. The reactants are preferably utilized instoichiometric proportions. The tricyclic dihydropyrazine compoundsobtained upon. ringclosure are then dehydrogenated as desired to providethe fused pyrazine ring.

It will accordingly be appreciated by those skilled in the art that when1,2-diaminocyclopentane and 1,2- cyclopentanedione are reacted, m and nin'the generic formula will both be one, while when 1,2- cyclodecadioneand 1,2-diaminocyclopentane are reacted m will be six and n will be one.Similar results will follow from the other reactions set forth aboveutilizing reactants having from five to ten carbon atoms in each ring.

The reaction can accordingly be represented as one between a cyclicketone having the formula and a cyclic amine having the formula whereinm and n are as set forth above; X is an amino group, a halo atom,preferably bromo or chloro,

or a carbonyl oxygen; and Y is an amino group or a carbonyl oxygen;except that X and Y cannot both be amino or both be carbonyl oxygen andX cannot be a halo atom when Y is carbonyl oxygen; and wherein R R R R RR R and R are the same or different and are hydrogen or lower alkyl.Thus, X and Y taken together is one of the following pairs of groups:

. X Y 1. carbonyl oxygen amino 2. halo atom amino 3. amino halo atom 4.amino carbonyl oxygen Examples of the l,2-diaminocycloalkanes which canbe used herein are:

1,2-diaminocyclopentane l,2-diaminocyclohexane;

l,2-diamino-4,5-dimethylcyclohexane;

l,2-diamino-3,3,5,5-tetramethylcycl0hexane; l,2-diamino-3,4,4-triethylcyclohexane;1,2-diamino-3,3-dimethyl-4,4-diethylcyclohexane;

l ,2-diaminocycloheptane;

. l,2-diamino-5-methylcycloheptane;

l,2-diamino-3,3 ,5 ,5 -tetramethylcyclohexane;

. l,2-diamino-3,3-dimethyl-5,5-diethylcycloheptane;

l,2-diarnino-3,7-dimethylcyclodecane; andl,2-diamino-3-methylcyclopentane.

Examples of the 2-halo-cycloalkanones are:

2-chlorocyclohexanone;

2-bromocyclohexanone; 2-chloro-3,4 dimethylcyclohexanone;2-chloro-3,3,5,5-tetramethylcyclohexanone; Z-bromocycloheptanone;2-bromo-3,4,5-triethylcycloheptanone;2-bromo-3,4,5,6-tetramethylcycloheptanone; and2-chloro-5-methylcyclodecanone Examples of the 1,2-cycloalkadionescapable of being utilized herein are:

3-methyll ,2-cyclopentadione;

l ,2-cyclodecadione;

4,4-dimethyl-ethyl-cyclodecadione; ione;

3 ,7-diethyl-1,2-cyclononadione;

3,4,5-trimethyl-7 ethyl-l ,2-cyclononadione;

1 ,2-cyclonondione;

l ,2-cyclooctadione;

3 methyl- 1 ,2-cyclohexadione;

4-methyll ,2-cycloheptadione;

1,2-cycloheptadione; and

l ,2-cyclopentadione.

Examples of amino cycloalkanones capable of being utilized herein are:

2-aminocyclopentanone-l 2-aminocyclohexanone-l Z-aminocycloheptanone-lZ-aminocyclooctanone- 1;

2-aminocyclodecanonel;

2-amino-4-methylcyclononanone-l 2'amino-3,3-dimethylcyclopentanonel; and

2-amino-3-methyl-4 ethylcyclohexanonel.

The reaction of the diamine and diketone is carried out at a temperatureof from 0 C. At temperatures lower than 0 C, the reaction rate isrelatively slow, while at temperatures higher than about 100 C, thereactants tend to polymerize. It is preferred to carry the reaction outat temperatures of from C to C. The time for the reaction to form thetricyclic pyrazine is from about 1 hour up to 8 hours. It is desirableto -cyclononadconduct the reaction so that the time required is fromabout 2 to about 4 hours.

In order to promote a more uniform reaction by moderating the rate andproviding good mixing and to facilitate removal by azeotropicdistillation of the water formed in the reaction, it is desirable insome aspects of the invention to utilize a liquid reaction vehicle. Thevehicle is desirably a solvent for the reactants and any otheringredients which are present in the reaction mixture and forms anazeotrope with water. The vehicle can also be chosen so that the refluxtemperature of the reaction mixture is within the temperature ranges ashereinbefore set forth. Thus, the preferred reaction vehicles utilizedat reaction temperatures above 15C include aromatic hydrocarbons such asbenzene, toluene, xylene, and the like. Vehicles which can be utilizedat lower reaction temperatures of 0 to C include aliphatic alcohols suchas methanol ethanol, isopropanol, and the like and aliphatic andalicyclic ethers such as tetrahydrofuran, diethyl ether, and the like.It will be understood that the alcohols can also be used at temperaturesof 15 C and above.

The reaction is desirably carried out-in the presence of a catalyst topromote the ring-closing reaction'and form the reduced pyrazine ring.The catalysts are generally acid substances, particularly aryl sulfonicacids such as paratoluene sulfonic acid and the like. Based upon thequantity of reactants, it is desirable to use from about 0.5 to aboutfive percent of such catalysts. All parts, proportions, percentages, andratios herein are by weight unless otherwise indicated.

After the formation of the reduced tricyclic pyrazine, it is oxidized toprovide the corresponding pyrazine derivative. This is carried out at analkaline pH obtained by adding a strong alkali metal hydroxide or anequivalent material such as alkali metal carbonate. The hydroxides ofsodium or potassium are desirably used.

The hydroxide-containing mixture is then treated with oxygen at atemperature of from to 70 C to provide a satisfactory reaction ratewhile minimizing undesirable side reactions and the ebullition of thereactants. The oxygen can be pure or can contain inert diluents. Air canbe used as the oxygen source.

The oxygen is added to the reactants by sparging or otherwise bubblingthe gas through the reaction mixture. At the temperatures used herein,the times for the reaction range from about 30 minutes to 24 hours, andit is desirable to carry out the reaction so that it attains a highdegree of completion in from about one to five hours.

The oxidation reaction is desirably carried out in an inert reaction,vehicle to reduce polymer formation, to permit better control over thereaction temperature, and to improve mixing of the reactants. Thepreferred inert reaction vehicles are solvents and include alkanols,preferably lower alkanols such as methanol, ethanol and the like.

After the reaction is complete, as readily determined by gaschromatography, the pH of the reaction mixture can, if desired, bereduced by the addition of an acid, desirably a strong mineral acid suchas dilute sulfuric acid, preferably 10 percent to 50 percent sulfuricacid. If any undissolved hydroxide exists at this point then it ispreferred that it be removed, as by centrifugation or filtration. Thecrude tricyclic pyrazine is then stripped of vehicle and furtherpurified as desired according to the procedures hereinafter described.

It will be understood by those skilled in the art that the intermediateand the final products prepared herein are washed and dried to obtainthe desired substances. The novel tricyclic pyrazines can be obtained inpurer form or in substantially pure form by conventional purificationtechniques. Thus, the products can be purified and/or isolated bydistillation, extraction, crystallization, preparative chromatographictechniques, and the like. It has been found desirable to purify thetricyclic pyrazines by fractional distillation under vacuum.

It will be appreciated from the present disclosure that the tricyclicpyrazines and mixtures thereof according to the present invention can beused to alter, vary, fortify, modify, enhance, or otherwise improve theflavor of a wide variety of materials which are ingested, consumed, orotherwise organoleptically sensed.

The term alter in its various forms will be understood herein to meanthe supplying or imparting a flavor character or note to an otherwisebland, relatively tasteless substance, or augmenting an existing flavorcharacteristic where the natural flavor is deficient in some regard, orsupplementing the existing flavor impression to modify organolepticcharacter.

Such pyrazines are accordingly useful in flavoring compositions. Aflavoring composition is taken to mean one which contributes a part ofthe overall flavor impression by supplementing or fortifying a naturalor artificial flavor in a material or one which supplies substantiallyall the flavor and/or aroma character to a consumable article.

The term foodstuff as used herein includes both solid and liquidingestible materials for man or animals, which materials usually do, butneed not, have nutritional value. Thus, foodstuffs includes meats,gravies, soups, convenience foods, malt, alcoholic, and other beverages,milk and dairy products, seafoods including fish, crustaceans, mollusks,and the like, candies, vegetables, cereals, soft drinks, snacks, dog andcat foods, other veterinary products, and the like.

The term tobacco" will be understood herein to mean natural productssuch as, for example, burley, Turkish tobacco, Maryland tobacco,flue-cured tobacco and the like including tobacco-like or tobaccobasedproducts such as reconstituted or homogenized leaf and the like, as wellas tobacco substitutes intended to replace natural tobacco, such aslettuce and cabbage leaves and the like. The tobaccos and tobaccoproducts include those designed or used for smoking such as incigarette, cigar, and pipe tobacco, as well as products such as snuff,chewing tobacco, and the like.

When the tricyclic pyrazines of this invention are used in a flavoringcomposition, they can be combined with conventional flavoring materialsor adjuvants. Such coingredients or flavoring adjuvants are well knownin the art for such use and have been extensively described in theliterature. Apart from the requirement that any such adjuvant materialbe ingestibly acceptable, and thus non-toxic or otherwisenon-deleterious, conventional materials can be used and broadly includeother flavor materials, vehicles, stabilizers, thickeners, surfaceactive agents, conditioners, and flavor intensifiers.

Such conventional flavoring materials include saturated, unsaturated,and amino acids; alcohols, including primary and secondary alcohols;esters; carbonyl compounds including ketones and aldehydes; lactones;other cyclic organic materials including benzene derivatives,alicyclics, heterocyclics such as furans, pyridines, other pyrazines andthe like; sulfur-containing materials including thiols, sulfides,disulfides and the like; proteins; lipids; carbohydrates; so-calledflavor potentiators such as monosodium glutamate, guanylates, andinosinates; natural flavoring materials such as cocoa, vanilla, andcaramel; essential oils and extracts such as anise oil; clove oil; andthe like; artificial flavoring materials such as vanillin; and the like.

Stabilizers include preservatives such as sodium chloride, and the like,antioxidants such as calcium and sodium ascorbate, ascorbic acid,butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate andthe like, sequestrants such as citric acid, EDTA, phosphates, and thelike.

Thickeners include carriers, binders, protective colloids, suspendingagents, emulsifiers and the like, such as agar-agar, carrageenan,cellulose and cellulose derivatives such as carboxymethyl cellulose andmethyl cellulose, natural and synthetic gum such as gum arabic, gumtragacanth, and the like, and other proteinaceous materials, lipids,carbohydrates, starches, and pectins.

Surface active agents include emulsifying agents such as monoand/ordiglycerides of fatty acids such as capric acid, caprylic acid, palmiticacid, myristic acid, stearic acid, oleic acid, and .the like, lecithin,defoaming and flavor-dispersing agents such sorbitan sorbitonmonostearate, potassium stearate, hydrogenated tallow alcohol, and thelike.

Conditioners include compounds such as bleaching and maturing agentssuch as benzoyl peroxide, calcium peroxide, hydrogen peroxide and thelike; starch modifiers such as peracetic acid, sodium chlorite, sodiumhypochlorite, propylene oxide, succinic anhydride and the like, buffersand neutralizing agents such as sodium acetate, ammonium bicarbonate,ammonium phosphate, citric acid, lactic acid, vinegar and the like;colorants such as carminic acid, cochineal, turmeric, curcumin and thelike; firming agents such as aluminum sodium sllfate, calcium chlorideand calcium gloconate; texturizers; anti-caking agents such as aluminumcalcium sulfate and tribasic calcium phosphate; enzymes; yeast foodssuch as calcium lactate and calcium sulfate; nutrient supplements suchas iron salts such as ferric pyrophosphate, ferrous gluconate and thelike, riboflavin, vitamins, zinc sources such as zinc chloride, zincsulfate, and the like.

The tricyclic pyrazines, or the compositions incorporating them, asmentioned above, can be combined with one or more vehicles or carriersfor adding them to the particular product. Vehicles can be edible orotherwise suitable materials such as ethyl alcohol, propylene glycol,water, and the like. Carriers include materials such as gum arabic,carrageenan, other gums, and the like. The tricyclic pyrazines can beincorporated with the carriers by conventional means such asspray-drying, drum-drying, and the like. Such carriers can also includematerials for coacervating the pyrazines (and other flavoringingredients, as present) to provide encapsulated products. When thecarrier is an emulsion, the flavoring composition can also containemulsifiers such as mon'oand diglycerides of fatty acids and the like.With these carriers or vehicles the desired physical form of thecomposition can be prepared.

It will be understood by those skilled in the art that the tricyclicpyrazines can be added during production of the finished product. Thus,when the pyrazines are used to alter or otherwise vary the flavor of afoodstuff, they can be added in the original mixture, dough, emulsion,batter, or the like prior to any cooking or heating operation.Alternatively, they can be added at a later stage of processing ifvolatilization losses would be excessive during the earlier processing.

When the materials are used to treat tobacco products, for example, theadditive can be applied in a suitable manner, as by spraying, dipping,or otherwise. The pyrazines can be applied during the casing" or finalspray treatment of the tobaccoor they can be applied at some earlierstage of curing or preparation. The quantity of pyrazines or mixturesthereof utilized should be sufficient to impart the desired flavorcharacteristic of the product, but on the other hand, the use of anexcessive amount of the pyrazines is not only wasteful and uneconomicalbut in some instances too large a quantity may unbalance the flavor orother organoleptic property of the product consumed. The quantity usedwill vary depending upon the ultimate foodstuff, tobacco product, orother consumable product; the amount and type of flavor initiallypresent in the product; the further process or treatment steps to whichthe product will be subjected; regional and other preference factors;the type of storage, if any, to which the product will be subjected; andthe pre-consumption treatment, such as baking. frying, and so on, givento the product by the ultimate consumer. Accordingly, the terminologyeffective amount and sufficient amount is understood in the context ofthe present invention to be quantitatively adequate to alter the flavorof the foodstuff, tobacco, or other consumable material.

It is preferred that the ultimate compositions contain from about 0.]part per million (ppm) to about 100 ppm of tricyclic pyrazines. Moreparticularly, in food compositions it is desirable to use from about 0.1to about 50 ppm and in certain preferred embodiments of the invention,from about 1 to about 15 ppm of the pyrazines-are included in thefinished product. On the other hand, tobacco compositions can contain aslittle as 0.1 ppm and as much as 100 ppm, depending upon whether acigarette tobacco, a pipetobacco, a cigar tobacco, a chewing tobacco, orsnuff is being prepared.

The amount of tricyclic pyrazine or pyrazines to be utilized in theflavoring composition can be varied over a wide range depending upon aparticular quality to be added to the foodstuff, tobacco, or otherconsumable material. Thus, amounts of one or more tricyclic pyrazinesaccording to the present invention from about 0.1 percent up to orpercent can be incorporated in such compositions. it is generally foundto be desirable to include from about 0.5 to about 25% of the tricyclicpyrazines in such compositions.

The tricyclic pyrazines of this invention are also useful individuallyor in admixtures as fragrances. They can be used to contribute a fatty,nut-like aroma. As olfactory agents the tricyclic pyrazines of thisinvention can be formulated into or used as components of a perfumecomposition."

The term perfume composition is used herein to mean a mixture of organiccompounds, including, for example, alcohols, aldehydes, ketones,nitriles, esters, and frequently hydrocarbons which are admixed so thatthe combined odors of the individual components produce a pleasant ordesired fragrance. Such perfume compositions usually contain: (a) themain note or the bouquet" or foundation-stone of the composition; (b)modifiers which round-off and accompany the main note; (c) fixativeswhich include odorous substances which lend a particular note to theperfume throughout all stages of evaporation, and substances whichretard evaporation; and (d) top-notes which are usually lowboiling freshsmelling materials.

In perfume compositions the individual component will contribute itsparticular olfactory characteristics, but the overall effect of theperfume composition will be the sum of the effect of each ingredient.Thus, the individual compounds of this invention, or mixtures thereof,can be used to alter the aroma characteristics of a perfume composition,for example, by highlighting or moderating the olfactory reactioncontributed by another ingredient in the composition.

The amount of the compounds of this invention which will be effective inperfume compositions depends on many factors, including the otheringredients, their amounts, and the effects which are desired. It hasbeen found that perfume compositions containing as little as 2 percentof the tricyclic pyrazines of this invention, or even less, can be usedto impart a scent to or alter the scent of soaps, cosmetics, and theother products. The amount employed can range up to 50% or higher andwill depend on considerations of cost, nature of the end product, theeffect desired on the finished product and particular fragrance sought.

The tricyclic pyrazines of this invention can be used alone or in aperfume composition as an olfactory component in detergents and soaps;space odorants and deodorants; perfumes; colognes; toilet waters; bathpreparations such as bath oil and bath salts; hair preparations such aslacquers, brilliantines, pomades, and

' shampoos; cosmetic preparations such as creams, de-

odorants, hand lotions, and sun screens; powders such as talcs, dustingpowders, face powder, and the like. When used as an olfactory componentof a perfumed article, as little as 0.0] percent of one or more of thetricyclic pyrazines will sufiice to impart a nut-like or honey odor.Generally, no more than 0.5 percent is required.

In addition, the perfume composition can contain a vehicle or carrierfor the tricyclic pyrazines alone or with otheringredients. The vehiclecan be a liquid such as alcohol, glycol, or the like. The carrier can bean absorbent solid such as a gum or components for encapsulating thecomposition.

The following examples are given to illustrate embodiments of theinvention as it is presently-preferred to practice it. It will beunderstood that these examples are illustrative, and the invention isnot to be considered as restricted thereto except as indicated in theappended claims.

EXAMPLE 1 Preparation of l-Methyl-2,3,5,6,7,8-hexa.hydrol(H)-cyclopenta[b]quinoxaline A three-liter flask equipped with condenser, stirrerheater, and Bidwell trap, is charged with the following ingredients:

ingredient Amount Cyciotcne 3-methyl- 1,2-cyclopentanedione) 34.8 g

l,2-Diaminocyclohexane 34.2 g P Toluene sulfonic acid 2 g Anhydrousbenzene l-.5 liters The mixture is refluxed at atmospheric pressure forthree hours, during which time 12 ml of water is collected in theBidwell trap. The reaction mass is then cooled and the benzene isstripped off at reduced pressure. The 53 grams of solid residue materialis then sublimed to obtain 29 grams of l-methyl-3,4a,5,6,7,8,8a,9-octahydro-2(H)-cyclopenta[b]quinoxaline having the structure:

/N NB The structure is confirmed by proton magnetic resonance (PMR)analysis Ten grams of the material produced above is charged to aone-liter flask, together with 38 ml of ethanol and 2 g of solidpotassium hydroxide. The reaction mixture is cooled to 20 C, and oxygenis bubbled into the mixture for one hour. The oxygen-saturated reactionmass is then heated to 50 C, and oxygen is again bubbled in for anotherhour, while the reaction mass is maintained at 50 C. v

The reaction mass is cooled, the ethanol is stripped off at reducedpressure, and the residue is then extracted with four 150 ml volumes ofether and washed with 100 ml of saturated sodium chloride solution.

The ether extract is dried over anhydrous magnesium sulfate and thedried solution is stripped of ether.

The resulting solid material has a nut-like aroma and the followingstructure:

As confirmed by PMR and mass spectral analysis.

EXAMPLE I] Preparation of l,2,3,4,6,7,8,9-Octahydrophenazine A two-literflask equipped with condenser, stirrer, and Bidwell trap is charged withthe following ingredients:

Ingredient Amount Cyclohexane-l,2-dione 9.65 g l,2-Diaminocyclohexane11.4 g P-Toluene sulfonic acid 1.0 g

l liter Benzene, anhydrous This structure is confirmed by PMR andinfrared (IR) analyses.

A one-liter flask is charged with 15 g of the decahydrophenazinedissolved in 300 ml of percent ethanol, 4 g of potassium hydroxide isadded, and oxygen is bubbled into the reaction mass for 1 hour at 20 Cand then for 1 hour at 50 C. The reaction mass is cooled, dissolved inwater, and extracted with diethyl ether. The ether extract is evaporatedand the residue is dissolved in 160 ml of 95 percent ethanol. Six gramsof potassium hydroxide are added to the alcoholic solution and themixture is refluxed for four hours .whereafter the mixture is cooled andthe ethanol is stripped off to provide a white solid. This solid isextracted with three 150 ml volumes of diethyl ether, and the etherextract is washed with the saturated sodium chloride solution. The etherextract is dried over anhydrous magnesium sulfate and stripped of ether.The resulting 4 g is distilled at a temperature in the range of 125 130C and a pressure of 2.0 2.5 mm Hg. NMR, IR and mass spectral analysisconfirm the structure:

The yellowish viscous liquid has the taste of fried corn chips at alevel of 5 ppm.

EXAMPLE Ill Preparation of l,2,3,4,6,7,8,9,l0,11,12,13-Dodecahydrocyclo-deca-[b]quinoxaline A 2-liter reaction vessel equippedwith stirrer, reflux condenser, and Bidwell trap is charge with:

Ingredient Amount Cyclodecane-l,2-dione g l,2Diaminocyclohexane 6.6 gP-Toluene sulfonic acid 1.5 g Benzene, anhydrous 1 liter The mixture isrefluxed for two hours until 25 ml of water is collected in the Bidwelltrap. The reaction mass is then cooled and the benzene stripped off toyield 21 g of a solid residue. This material is determined by massspectral analysis and PMR to be the reduced pyrazine having thestructure:

The 21 grams of solid is dissolved in 250 ml of ethanol in a 1-literflask, 6 grams of potassium hydroxide is added, and the reaction mixtureis refluxed for three horus and then cooled. The ethanol is stripped offand the residue dissolved in 100 ml of saturated sodium chloridesolution. The sodium chloride solution is extracted four times with 150ml portions of ether. The extracts are combined and then dried overanhydrous magnesium sulfate. The dried ether extract is stripped ofother. The resulting 21 g of residue is distilled at a temperature in arange of l60-l66C at 2 mm Hg. PMR, IR and mass spectral analysis showsthat the material isl,2,3,4,6,7,8,9,l0,11,12,13-dodecahydrocyclodeca[b]quinoxaline havingthe structure:

This material has a light, sweet, nut character.

EXAMPLE iv A basic cocoa flavor material is prepared by admixing thefollowing materials:

A nut-like flavor note material is prepared by combining the followingingredients as shown:

Ingredient Amount (parts) Material produced in Example I l 1.0

Material produced in Example 11 27.0

Material produced in Example III 20.0 Total: 58.0

A first flavor composition is prepared by a 1.2 percent dilution-of thebasic cocoa flavor in propylene glycol/ethyl alcohol (v/v /20). Vanillinis added in the ratio of 250 mg. per kilogram of solution. A secondflavor composition is prepared by a 2% dilution of the basic cocoaflavor combined with the nut-like flavor note material (weight ratio84.2:58.0) in propylene glycol/ethyl alcohol (v/v 80/20) Vanillin isadded in the ratio of 250 mg. per kilogram of liquid.

The combined flavor (2 percent dilution) thus prepared is found to havean excellent cocoa flavor and aroma note, whereas the flavor without thetricyclic pyrazines of this invention lacks the desirable nut-likeflavor note.

EXAMPLE V EXAMPLE VI A flavor composition accordingto this invention isprepared by combining the following materials as shown:

COMPOUND Tricyclic yrazlne of Examp e I 6 Tricyclic pyrazine of Example11 Tricyclic pyrazine of Example III AMOUNT (grams) This tricyclicpyrazine composition is added to a chocolate milk having a bland, thincocoa flavor. Adding 30 mg/kg increases the nut-like note, andsupplemental addition of 40 mg/kg of the basic cocoa flavor material asdescribed in Example IV gives the chocolate milk an excellent cocoaflavor and aroma note.

EXAMPLE VII A commercial cocoa mix is used to prepare two differentbatches of beverage. The first batch is evaluated without any furtheradditive, while the material of Example I is added to the second batchin the ratio of 40 mg of the tricyclic pyrazine to each kilogram ofcocoa beverage. The beverage without tricyclic pyrazine gives a ratherharsh flavor impression, while the beverage containing tricyclicpyrazine according to the present invention has a fuller, richer cocoaflavor.

EXAMPLE VIII The aroma provided by the l,2,3,4,6,7,8,9-octahydrophenazine (as produced in Example II) in the composition setforth below is important to the natural" undertone quality of thecertain floral absolutes such as Hyacinth and Narcissus. The fonnulationis as follows:

octahydrophenazine lends an authentic, earthy, dank character bringingthe composition closer to the odor of pure Hyacinth absolute,

EXAMPLE IX A perfume composition is prepared by admixing the followingingredients:

AMOUNT 40 20 The small amount of I,2,3,4,6,7,8,9- octahydrophenazinesignificantly improves the total effect of the fragrance, imparting thenecessary rooty, potato-like nutty character to the mixture of the otherwoody materials.

I What is claimed is:

l. A process for altering the flavor of a consumable material whichcomprises adding thereto a small but effective amount of at least onetricyclic pyrazine having the formula:

wherein m and n are the same or different and are integers from one tosix, inclusive, the sum of m ane n not being greater than eight, and R RR R R R,,, R, and R are hydrogen or lower alkyl.

2. A process according to claim 1 wherein the alkyl group or groups,when present, have from one to three carbon atoms, inclusive.

3. A process according to claim 1 wherein the consumable material is afoodstuff.

4. A process according to claim 1 wherein the consumable material is atobacco.

5. A process according to claim 1 wherein m is one, n is two, R, ismethyl, and R R R R R R-,, and R are hydrogen.

6. A process according to claim 1, wherein m is six, n is two, and R R RR R R R and R are hy drogen.

7. A flavoring composition containing at least one tricyclic pyrazineaccording to claim 1 and a vehicle or carrier.

a: s s r a:

was UNITED STATES PATENT OFFICE Patent No. 3,754,934 D ed August 28,1973 Inventofls) ALAN o. PITTET'and RANYA MURALIDHARA It is certifiedthat error appears in the above-identified patent and that said LettersPatent-ere hereby corrected as shown below:

Col. '2, line 45, correct the formula toreach I Col. 2, lines 55-- 60-,o'rrect hthe formnl a to read-i:

Col. 3, l. 30, correct spelling of "halocycloalkanon-e' Col. 4, lines'41 and 42, delete "-cyclononedione". I

'Col. 7, line 29, after "such"'an'd before "sorb i tan" insert -as-; andstrike "sorbiton Col. 7, line 42, correct the spelling of "sulfate", andY'gluconate".

Col. 11', line 52, correct the spelling of "'hours' Claim 1, third fromlast line thereof, correct the spelling of ,"and".

Signed and sealed this 18th day of December 1973.

(SEAL) i attest:

EDWARD u FLETCHER, J page flfEGTME-YER Attesping Officer Acting;Qonlmissioner oi Patents @ERTIFICATE OF CORRECTIQN IFF 2164A-

2. A process according to claim 1 wherein the alkyl group or groups,when present, have from one to three carbon atoms, inclusive.
 3. Aprocess according to claim 1 wherein the consumable material is afoodstuff.
 4. A process according to claim 1 wherein the consumablematerial is a tobacco.
 5. A process according to claim 1 wherein m isone, n is two, R1 is methyl, and R2, R3, R4, R5, R6, R7, and R8 arehydrogen.
 6. A process according to claim 1, wherein m is six, n is two,and R1, R2, R3, R4, R5, R6, R7, and R8 are hydrogen.
 7. A flavoringcomposition containing at least one tricyclic pyrazine according toclaim 1 and a vehicle or carrier.